In the case of electrodes conventionally used for the measurement of electric potentials of the human body (as in the case of electrocardiographic electrodes) or for stimulation in pacemakers and therapy, etc., the electrodes are retained on the surface of the skin by suction, using a suction disk at each measurement position on the body (e.g., thorax, etc.). Specifically, the electrodes are set in place following a pre-treatment in which the surface of the skin is coated with a conductive jelly, etc.
Furthermore, a system is also used in which the electrodes are fixed in place by means of adhesive tape. In such cases, the electrodes used are generally metal electrodes.
In the case of the above mentioned conventional electrodes using suction disks, there are difficulties in electrode retention (e.g., in cases where the negative pressure of the suction disks is weak, the suction force may be lost as a result of slight movements of the body or perspiration, etc.). Accordingly, it is difficult to perform electrocardiographic measurements over a long period of time using such electrodes. Furthermore, as a result of the need to apply a conductive jelly, etc., to the surface of the skin in order to improve the conductivity of the suction attachment, the setting of the electrodes on the body takes time, which is especially inconvenient in emergency cases.
Furthermore, if the negative pressure of the suction disks is too strong, subcutaneous hemorrhaging may occur (in the chest wall, etc.). Accordingly, there are unavoidable limitations on the negative pressure that can be used.
In cases where adhesive tape is used, reddening of the skin commonly occurs. This gives the patient an unpleasant sensation, and the patient commonly experiences discomfort in the case of long-term recording.
Furthermore, in the case of conventional metal electrodes, there is a feeling of weight when the electrodes are applied to the measurement positions on the skin. Since such electrodes are rigid and therefore do not readily conform to the contours of the skin surface, the effective contact area is limited. Furthermore, such electrodes may easily slip off.